header {
  display: flex;
  height: 80px;
  background-color: tomato;
}

header>.logo {
  flex: 1;
  background-color: #999;
  text-align: center;
  font: bolder normal 1.3rem/80px "微软雅黑";
  letter-spacing: .5rem;
  color: #ffffff;
}

header>.useName {
  flex: 5;
  background-color: thistle;
  border: 2px solid #777777;
  border-left: 0;
}

content {
  display: flex;
  height: calc(100% - 80px);
  background-color: violet;
}

content>aside {
  flex: 1;
  background-color: yellow;
  position: relative;
}

content>aside>div:not(:last-of-type) {
  margin-top: 20px;
  height: 50px;
  background-color: red;
  font: normal normal .98rem/50px "微软雅黑";
  border-left: 4px solid blue;
  padding-left: 40px;
  cursor: pointer;
}

content>aside>div:last-of-type {
  width: 100%;
  height: 40px;
  line-height: 40px;
  text-align: center;
  font: normal normal .85rem/40px "微软雅黑";
  color: #999;
  background-color: thistle;
  position: absolute;
  left: 0;
  bottom: 0;
}

content>main {
  flex: 5;
  background-color: bisque;
}